Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/10—Homopolymers or copolymers of propene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/10—Homopolymers or copolymers of propene
  • C08L23/12—Polypropene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/16—Elastomeric ethene-propene or ethene-propene-diene copolymers, e.g. EPR and EPDM rubbers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L51/00—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
  • C08L51/06—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond

Definitions

• the present invention concerns polyolef ⁇ n compositions containing fillers, having an improved balance of processability and mechanical properties.
• compositions of the present invention allow to achieve relatively high values of Melt Flow Rate, hereinafter abbreviated into MFR, notwithstanding the presence of significant and even very high amounts of fillers, associated with a very favorable and unusual balance of mechanical properties.
• reinforced polypropylene compositions with good impact properties are obtained by blending even high amounts of organic fibers and optionally inorganic fillers to a polypropylene resin having a MFR of from about 20 to about 1500 g/10 min..
• MFR MFR of from about 20 to about 1500 g/10 min.
• the highest MFR values of the propylene polymers used in the examples of the said document are of 400-430 g/10 min..
• compositions of the present invention are dimensional stability, creep resistance and environmental stress cracking resistance.
• compositions of the invention present also higher ability to fill cavity moulds, even with complex design, and bring to a reduction of cycle times in injection moulding applications.
• compositions of the present invention together with their higher stiffness values, makes it also possible to reduce the thickness of moulded items produced.
• filled polyolefm compositions comprising:
• MFR 1 Melt Flow Rate
• a polypropylene fraction A 11 having a Melt Flow Rate (MFR 11 ) value of from 0.1 to 30 g/10 min., the said percentages of A 1 ) and A 11 ) being referred to the sum of A 1 ) and A 11 ); or b) a polypropylene composition containing from 15% to 72% by weight of a polypropylene fraction A 1 ) having a Melt Flow Rate (MFR 1 ) value of 500 g/10 min. or more, from 15% to 70% by weight of a polypropylene fraction A 11 ) having a Melt Flow Rate (MFR 11 ) value of from 0.1 to 30 g/10 min.
• MFR 1 Melt Flow Rate
• compositions of the present invention comprise from 20 % to 70% by weight, more preferably from 30 % to 60 % by weight of A) and from 30 % to 80 % by weight, more preferably from 40 % to 70 % by weight of B) with respect to the total weight of A) and B).
• the fraction A 1 ) as defined above is a propylene polymer or polymer composition having very high MFR values, namely of 500 g/10 min. or more, preferably of 1200 g/10 min. or more, in particular from 500 to 2500 g/10 min. or from 1200 to 2500 g/10 min..
• the fraction A 1 ) is preferably made of as-polymerized propylene polymers, not subjected after polymerization to any treatment able to substantially change the MFR value.
• fraction A 1 are substantially those directly obtained in the polymerization process used to prepare the propylene polymers.
• the said MFR values are obtained by degradation
• the comonomers in the propylene copolymers that can be present in fraction A 1 ) are selected from ethylene and/or C 4 -C 10 ⁇ -olef ⁇ ns, such as for example butene-1, pentene-1, A- methylpentene-1, hexene-1 and octene-1.
• the preferred comonomers are ethylene and butene-1.
• All the propylene polymers and copolymers of fraction A 1 ) can be prepared by using a
• Ziegler-Natta catalysts are the supported catalyst systems comprising a trialkylaluminium compound, optionally an electron donor, and a solid catalyst component comprising a halide or halogen-alcoholate of Ti and optionally an electron-donor compound supported on anhydrous magnesium chloride.
• Catalysts having the above-mentioned characteristics are well known in the patent literature; particularly advantageous are the catalysts described in USP 4,399,054 and EP-A-45 977. Other examples can be found in
• the propylene polymers of fraction A 1 are prepared with Ziegler-Natta catalysts they have, at an MFR ranging from 600 to 1000 g/10 min., Mw values from
• Isotacticity Index in terms of weight fraction insoluble in xylene at room temperature (about 25 0 C) higher than or equal to 95%, more preferably higher than or equal to 97%.
• the propylene polymers of fraction A 1 are obtained directly in polymerization in the presence of a metallocene-based catalyst system.
• the polymerization conditions in general do not need to be different from those used with Ziegler-Natta catalysts.
• the preferred metallocene-based catalyst system is obtainable by contacting: a) a metallocene compound of formula (I):
• M is a transition metal belonging to group 3, 4, 5, 6 or to the lanthanide or actinide groups in the Periodic Table of the Elements; preferably M is titanium, zirconium or hafnium; X, same or different, are hydrogen atoms, halogen atoms, or R, OR, OSO 2 CF 3 , OCOR, SR, NR 2 or PR 2 groups, wherein R are linear or branched, cyclic or acyclic, Q-Gto-alkyl, C 2 -C 4 O alkenyl, C 2 -C 4 O alkynyl, C 6 -C 40 -aryl, C 7 -C 4 o-alkylaryl or C 7 -C 4 o-arylalkyl radicals; optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; preferably R is a linear or branched Ci-C 2 o-alkyl radical; or two X can optionally form a substituted or unsub
• L is a divalent Ci-C 4O hydrocarbon radical optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements or a divalent silylidene radical containing up to 5 silicon atom; preferably L is a divalent bridging group selected from Ci-C 4 O alkylidene, C 3 -C 40 cycloalkylidene, C 6 -C 4 O arylidene, C 7 - C 4 o alkylarylidene, or C 7 -C 4 O arylalkylidene radicals optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements, and silyliene radical containing up to 5 silicon atoms such as SiMe 2 , SiPh 2 ; preferably L is a group (Z(R") 2 ) n wherein Z is a carbon or a silicon atom, n is 1 or 2 and R" is a Ci-C 2 O hydrocarbon radical optionally containing heteroatoms belonging to groups
• R 1 is a C 1 -C 40 hydrocarbon radical optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; preferably R 1 is a linear or branched, cyclic or acyclic, Ci-C4o-alkyl, C 2 -C 4 O alkenyl, C 2 -C 4 O alkynyl, C6-C4o-aryl, C 7 -C 4 o-alkylaryl or Cy-C 4 o-arylalkyl radical; optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; more preferably R 1 is a linear or branched, saturated or unsaturated Ci-C 2 o-alkyl radical;
• R 2 , R 3 R 4 and R 5 are hydrogen atoms or C1-C40 hydrocarbon radicals optionally containing heteroatoms belonging to groups 13-17 of the
• Periodic Table of the Elements or two R groups among R 2 , r R> 3 r R, 4 and j r R> 5 form a C4-C ring that can be unsaturater or saturated optionally containing containing heteroatoms belonging to groups 14-16 of the Periodic Table of the Elements; the ring formed can bear Ci-C 2 O hydrocarbon substituents; b) at least an alumoxane or a compound able to form an alkylmetallocene cation.
• metallocene compound a) is rac-dimethylsilylbis(2-methyl-4, 5- benzo-indenyl)-zirconium dichloride.
• the alumoxanes are considered to be linear, branched or cyclic compounds containing at least one group of the type: wherein the substituents U, same or different, are hydrogen atoms, halogen atoms, C 1 -C 20 -alkyl, C 3 -C 20 -cyclalkyl, C 6 -C 2 o-aryl, C 7 -C 2 o-alkylaryl or C 7 -C 2 o-arylalkyl radicals, optionally containing silicon or germanium atoms, with the proviso that at least one U is different from halogen.
• the substituents U same or different, are hydrogen atoms, halogen atoms, C 1 -C 20 -alkyl, C 3 -C 20 -cyclalkyl, C 6 -C 2 o-aryl, C 7 -C 2 o-alkylaryl or C 7 -C 2 o-arylalkyl radicals, optionally containing silicon or germanium
• n 1 is O or an integer of from 1 to 40 and the substituents U are defined as above; or alumoxanes of the formula:
• (Al — O)n 2 can be used in the case of cyclic compounds, wherein n 2 is an integer from 2 to 40 and the U substituents are defined as above.
• alumoxanes examples include methylalumoxane (MAO), tetra-(isobutyl)alumoxane (TIBAO), tetra-(2,4,4-trimethyl-pentyl)alumoxane (TIOAO), tetra-(2,3- dimethylbutyl)alumoxane (TDMBAO) and tetra-(2,3,3-trimethylbutyl)alumoxane (TTMBAO).
• MAO methylalumoxane
• TIBAO tetra-(isobutyl)alumoxane
• TIOAO tetra-(2,4,4-trimethyl-pentyl)alumoxane
• TDMBAO tetra-(2,3- dimethylbutyl)alumoxane
• TTMBAO tetra-(2,3,3-trimethylbutyl)alumoxane
• Examples of compounds able to form an alkylmetallocene cation are compounds of formula D + E " , wherein D + is a Br ⁇ nsted acid, able to donate a proton and to react irreversibly with a substituent X of the metallocene of formula (I) and E " is a compatible anion, which is able to stabilize the active catalytic species originating from the reaction of the two compounds, and which is sufficiently labile to be removed by an olefmic monomer.
• the anion E " comprises one or more boron atoms.
• the anion E " is an anion of the formula BAr 4 , wherein the substituents Ar which can be identical or different are aryl radicals such as phenyl, pentafluorophenyl or bis(trifluoromethyl)phenyl. Tetrakis-pentafluorophenyl borate is particularly preferred compound, as described in WO 91/02012.
• compounds of formula BA ⁇ 3 can be conveniently used. Compounds of this type are described, for example, in the International patent application WO 92/00333.
• Other examples of compounds able to form an alkylmetallocene cation are compounds of formula BA ⁇ P wherein P is a substituted or unsubstituted pyrrol radical.
• All these compounds containing boron atoms can be used in a molar ratio between boron and the metal of the metallocene comprised between about 1 :1 and about 10:1; preferably 1 :1 and 2:1; more preferably about 1 :1.
• propylene polymers prepared with a metallocene-based catalyst system are: distribution of molecular weight Mw/Mn lower than 4; more preferably lower than 3; most preferably lower than 2.7; isotactic pentads (mmmm) measured with 13 C-NMR, higher than 90%; more preferably higher than 92%; xylene solubles at 25°C below 2% by weight, more preferably below 1.6% by weight; melting point measured by means of DSC, higher than 143 0 C;
• the polypropylene fraction A 11 can be any propylene homopolymer or copolymer having a MFR value from 0.1 to 30 g/10 min..
• the said fraction A 11 ) can be prepared with conventional catalysts (Ziegler-Natta or metallocene-based) in conventional polymerization processes.
• Preferred features for the said polypropylene fraction A 11 ) are:
• MFR values from 0.5 to 20 g/10 min.
• Isotacticity Index in terms of weight fraction insoluble in xylene at room temperature (about 25 0 C) higher than or equal to 92%, more preferably higher than or equal to 95%; - amount of comonomer(s) up to 9% by moles, more preferably up to 5% by moles;
• melt strength measured at 230 0 C, higher than 1.50 cN, in particular ranging from
• Examples of comonomer(s) that can be present in A 11 ) are the same as previously defined for the polypropylene fraction A 1 ).
• fraction A 11 Specially preferred for use as fraction A 11 are compositions containing from 30% to 70% by weight, preferably from 40 % to 60 % by weight, of a fraction i) having a molecular weight distribution, in terms of Mw/Mn ratio, from 4 to 9, and from 30% to 70% by weight, preferably from 40 % to 60 % by weight, of a fraction ii) having a molecular weight distribution, in terms of Mw/Mn ratio, of higher than 10, said fractions i) and ii) being independently selected from propylene homopolymers and random copolymers of propylene containing up to 5% by moles of ethylene and/or C4-C10 ⁇ -olefm(s); the said percentages of i) and ii) being referred to the sum of i) and ii).
• the said fraction ii) can also be used as fraction A 11 ).
• the process is carried out in a first and in a second interconnected polymerization zone to which propylene and ethylene or propylene and alpha-olef ⁇ ns are fed in the presence of a catalyst system and from which the polymer produced is discharged.
• the growing polymer particles flow through the first of said polymerization zones (riser) under fast fluidization conditions, leave said first polymerization zone and enter the second of said polymerization zones (downcomer) through which they flow in a densif ⁇ ed form under the action of gravity, leave said second polymerization zone and are reintroduced into said first polymerization zone, thus establishing a circulation of polymer between the two polymerization zones.
• the conditions of fast fluidization in the first polymerization zone is established by feeding the monomers gas mixture below the point of reintroduction of the growing polymer into said first polymerization zone.
• the velocity of the transport gas into the first polymerization zone is higher than the transport velocity under the operating conditions and is normally between 2 and 15 m/s.
• the second polymerization zone where the polymer flows in densif ⁇ ed form under the action of gravity, high values of density of the solid are reached which approach the bulk density of the polymer; a positive gain in pressure can thus be obtained along the direction of flow, so that it becomes possible to reintroduce the polymer into the first reaction zone without the help of mechanical means.
• a "loop" circulation is set up, which is defined by the balance of pressures between the two polymerization zones and by the head loss introduced into the system.
• one or more inert gases such as nitrogen or an aliphatic hydrocarbon
• the operating parameters such as, for example, the temperature are those that are usual in gas-phase olefin polymerization processes, for example between 50°C and 120°C, preferably from 70 0 C to 90 0 C.
• the process can be carried out under operating pressure of between 0.5 and 10 MPa, preferably between 1.5 and 6 MPa.
• the various catalyst components are fed to the first polymerization zone, at any point of said first polymerization zone. However, they can also be fed at any point of the second polymerization zone.
• the polymerization process means are provided which are capable of totally or partially preventing the gas and/or liquid mixture present in the raiser from entering the downcomer and a gas and/or liquid mixture having a composition different from the gas mixture present in the raiser is introduced into the downcomer.
• the introduction into the downcomer, through one or more introduction lines, of said gas and/or liquid mixture having a composition different from the gas mixture present in the raiser is effective in preventing the latter mixture from entering the downcomer.
• the gas and/or liquid mixture of different composition to be fed to the downcomer can optionally be fed in partially or totally liquefied form.
• the molecular weight distribution of the growing polymers can be conveniently tailored by carrying out the polymerization process in a reactor diagrammatically represented in
• the filler component B) to be used in the compositions of the present invention can be organic or inorganic.
• fibers both organic and inorganic, and the other inorganic fillers (different from fibers), such as metallic flakes, glass flakes, milled glass, glass spheres and mineral fillers, like talc, calcium carbonate, mica, wollastonite or silicates in general, kaolin, barium sulfate, metal oxides and hydroxides.
• inorganic fillers such as metallic flakes, glass flakes, milled glass, glass spheres and mineral fillers, like talc, calcium carbonate, mica, wollastonite or silicates in general, kaolin, barium sulfate, metal oxides and hydroxides.
• Another suited filler is wood flour.
• Suitable fibers for the present compositions include fibers made of glass, metal, ceramic, graphite, and organic polymers such as polyesters and nylons, e.g., aramids, in filamentary form, all of which are commercially available.
• Glass fibers are preferred.
• the glass fibers may be either cut glass fibers or long glass fibers, or may be in the form of continuous filament fibers, although preference is given to using cut glass fibers, also known as short fibers or chopped strands.
• the glass fibers can have a length of from 1 to 50 mm.
• the cut or short glass fibers used in the compositions of the present invention preferably have a length of from 1 to 6 mm, more preferably from 3 to 4.5 mm, and a diameter of from
• the polypropylene compositions of the present invention can also comprise a compatibilizer Q).
• One type which can be used are low molecular weight compounds having reactive polar groups, which serve to make the fillers less hydrophilic and therefore more compatible with the polymer.
• Suitable compounds are, for example, silanes such as aminosilanes, epoxysilanes, amidosilanes or acrylosilanes.
• the compatibilizers preferably comprise a modified (functionalized) polymer and optionally a low molecular weight compound having reactive polar groups.
• Modified olefin polymers in particular propylene homopolymers and copolymers, like copolymers of ethylene and propylene with each other or with other alpha olefins, are most preferred, as they are highly compatible with the component A) of the compositions of the present invention.
• Modified polyethylene can be used as well.
• the modified polymers are preferably selected from graft or block copolymers.
• modified polymers containing groups deriving from polar compounds in particular selected from acid anhydrides, carboxylic acids, carboxylic acid derivatives, primary and secondary amines, hydroxyl compounds, oxazoline and epoxides, and also ionic compounds.
• the said polar compounds are unsaturated cyclic anhydrides and their aliphatic diesters, and the diacid derivatives.
• the low molecular weight compound serves to couple the filler to the modified polymer and thus to bind it securely to the propylene polymer component A). These are usually bifunctional compounds, in which case one functional group can enter into a binding interaction with the filler and the second functional group can enter into a binding interaction with the modified polymer.
• the low molecular weight compound is preferably an amino- or epoxysilane, more preferably an aminosilane.
• the aminosilanes bond with the silane hydroxyl groups to the glass fiber, while the amino groups form a stable amide bond, for example with polypropylene grafted with maleic anhydride.
• the modified polymer can be produced in a simple manner by reactive extrusion of the polymer, for example with maleic anhydride in the presence of free radical generators (like organic peroxides), as disclosed for instance in EP0572028.
• free radical generators like organic peroxides
• Preferred amounts of groups deriving from polar compounds in the modified polymers are from 0.5 to 3% by weight.
• MFR for the modified polymers are from 50 to 400 g/10 min..
• the polyolefm compositions according to the invention are obtainable by melting and mixing the components, and the mixing is effected in a mixing apparatus at temperatures generally of from 180 to 310 0 C, preferably from 190 to 280 0 C, more preferably from 200 to
• Useful mixing apparatus in this context are in particular extruders or kneaders, and particular preference is given to twin-screw extruders. It is also possible to premix the components at room temperature in a mixing apparatus.
• compositions of the present invention are:
• Density from 1.1 to 4 kg/dm , more preferably 1.1 to 1.8 kg/dm ;
• - Flexural Modulus from 2500 to 19000 MPa, more preferably 5000 to 17000 MPa;
• Charpy unnotched at 23 0 C from 30 to 200 kJ/m 2 , more preferably 35 to 65 kJ/m 2 ; Charpy unnotched at -30° C: from 30 to 150 kJ/m 2 , more preferably from 40 to 70 kJ/m 2 ;
• Charpy notched at 23 0 C from 5 to 200 kJ/m 2 , more preferably from 10 to 20 kJ/m 2 ;
• Charpy notched at -30° C from 5 to 150 kJ/m 2 , more preferably from 10 to 25 kJ/m 2 ;
• Tensile Strength at break from 50 to 150 MPa, more preferably from 80 to 140
• Elongation at break from 1 to 200 %, in partcular from 1 to 5 %;
• compositions of the present invention are:
• Density from 1.1 to 4 kg/dm 3 , more preferably 1.1 to 1.9 kg/dm 3 ;
• - Flexural Modulus from 2500 tol4000 MPa, more preferably 5000 to 12000 MPa;
• Charpy unnotched at 23 0 C from 3 to 25 kJ/m 2 , more preferably 4 to 20 kJ/m 2 ;
• Charpy notched at 23 0 C from 1 to 10 kJ/m 2 , more preferably from 1.5 to 7 kJ/m 2 ;
• Tensile Strength at break from 20 to 60 MPa, more preferably from 20 to 50
• compositions of the present invention can be used in many applications, like injection moulded articles, in particular parts for automotive, electrical appliances, furniture, or formed articles in general, in particular sheets, parts for electrical appliances, furniture, housewares, or as hyper-filled masterbatches.
• the amount of component B) is particularly high, indicatively from 50% to 80% by weight with respect to the total weight of A) and B)
• the compositions of the present invention can also be advantageously used as concentrates, to introduce fillers in polymer compositions, in particular polyolefm compositions, by blending with additional polymers.
• Intrinsic Viscosity Measured in tetrahydronaphthalene at 135° C;
• Test specimens are injection moulded according to Test Method ISO 1873-2 (1989). Determination of Isotacticity Index (solubility in xylene at room temperature, in % by weight)
• the percent by weight of polymer insoluble in xylene at room temperature is considered the isotacticity index of the polymer. This value corresponds substantially to the isotacticity index determined by extraction with boiling n-heptane, which by definition constitutes the isotacticity index of polypropylene.
• the Mn and Mw values are measured by way of gel permeation chromatography (GPC) at
• Trichlorobenzene (TCB) and the flow rate is kept at 1.0 ml/min.
• the sample solution is prepared by heating the sample under stirring at 145°C in TCB for two hours. The concentration is 1 mg/ml.
• 0.1 g/1 of 2,6- diterbutyl-p-cresol are added. 326.5 ⁇ L of solution are injected into the column set.
• a calibration curve is obtained using 10 polystyrene standard samples (EasiCal kit by Polymer Laboratories) with molecular weights in the range from 580 to 7500000; additionally two other standards with peak molecular weight of 11600000 and 13200000 from the same manufacturer are included. It is assumed that the K values of the Mark-Houwink relationship are:
• a third order polynomial fit is used for interpolate the experimental data and obtain the calibration curve.
• Data acquisition and processing is done by using Empower 1.0 with
• the mmmm content is obtained modelling the experimental pentad distribution with the enantiomorphic site model.
• [mmmm] 100 ( ⁇ [CH3]-5[mmn]-5[E]-5[H]) / ( ⁇ [CH3]) where ⁇ fCH ⁇ ] is the sum of all CH3 groups.
• [H] 100 (0.5 H 2 / ⁇ [CH2]) where Eg is the peak at 42.14 ppm, H 2 is the peak at 30.82 ppm and ⁇ [CH2] is the sum of all CH 2 groups.
• the apparatus used is a Toyo-Sieki Seisakusho Ltd. melt tension tester provided with a computer for data processing.
• the method consists in measuring the tensile strength of a strand of molten polymer stretched at a specific stretch velocity.
• the polymer to be tested is extruded at 230 0 C at 0.2 mm/min through a die with a capillary hole 8 mm long and 1 mm in diameter.
• the exiting strand is then stretched, by using a system of traction pulleys, at a constant acceleration of 0.0006 m/sec 2 , measuring the tension until the breaking point.
• the apparatus registers the tension values of the strand as a function of the stretching.
• the melt strength corresponds to the melt tension at polymer break.
• PP-I Propylene homopolymer, with MFR of 2300 g/10 min, Mw/Mn of 2.6 and isotacticity index in xylene at room temperature of 98.5% (isotactic pentades
• PP-2 Propylene homopolymer, with MFR of 12 g/10 min, Mw/Mn of 5.4 and isotacticity index of 96.7%, in form of pellets
• PP-3 Propylene copolymer containing 1.6% by weight of ethylene, with MFR of 3 g/10 min, Mw/Mn of 19.2 and isotacticity index of 96%, in form of pellets
• PP-4 Propylene homopolymer, with MFR of 550 g/10 min, Mw/Mn of 2.3 and isotacticity index in xylene at room temperature of 98.7% (isotactic pentades (mmmm) higher than 92%), DSC melting temperature of 145.3 0 C, intrinsic viscosity of 0.69 dl/g, in form of pellets
• PP-5 Propylene homopolymer, with MFR of 12 g/10 min, Mw/Mn of 5.4 and isotacticity index of 96.7%, in
• PP-I is obtained with a catalyst system prepared as described in PCT/EP2004/007061 by using rac-dimethylsilylbis(2-methyl-4, 5-benzo-indenyl)-zirconium dichloride.
• the catalyst system in the form of catalyst mud obtained as described in PCT/EP2004/007061 is fed in a precontact vessel in which it is diluted with about 5 (Kg/h) of propane. From the pre-contact vessel the catalyst system is fed to a prepolymerization loop in which propylene is fed at the same time.
• the prepolymerization temperature is of 45 0 C
• the residence time of the catalyst in the prepolymerization loop is 8 minutes.
• the prepolymerized catalyst obtained in the prepolymerization loop is then continuously fed into a loop reactor in which propylene is fed at a rate of 340 Kg/h.
• the polymerization temperature is of 70 0 C.
• the polymer is discharged from the loop reactor, separated from the unreacted monomer and dried.
• the MFR of the product is controlled by the feed of hydrogen, to be adjusted to get the required MFR of the polymer. In the case of PP-I the hydrogen concentration is of 1080 ppm.
• PP-4 is prepared in the same way as PP-I with the difference that propylene is fed at a rate of 329 Kg/h and the hydrogen feed is 550 ppm.
• Component A) contains also about 0.3% by weight of conventional antioxidant additives.
• Example 13 it contains also 300 ppm by weight of phthalocyanine blue (PV-Echtblau 2GL SP, Clariant).
• Example 14 it contains also 0.18% by weight of Millad 3988 3,4- dimethylbenzylidene sorbitol.
• composition are prepared by extrusion, using a twin screw extruder, model Werner&Pfleiderer ZSK40SC.
• This line has a process length of approx 43 L/D and is provided with gravimetric feeders.
• Components A) and Q) are fed into the first barrel and component B) is fed into the fifth barrel, via forced side feeding.
• a strand die plate with cooling bath and strand cutter Scheer SGSlOO is used to form pellets; vacuum degassing (barrel No. 8) is also applied to extract fumes and decomposition products.
• a single cavity endless spiral flow mould with 2.5 mm depth is used and the compositions of
• Example 3 and Comparative Example 2 are injected at a constant melt temperature of 230 0 C, at different injection pressures (2, 4, 6, 8, 10 MPa).
• the injection moulding machine was Sandretto Model 190 with 190 ton clamping force; mould temperature is 40 0 C
• the composition of Example 3 presents a much higher spiral flow length with respect to the composition of comparative Example 2. This means that the compositions of the invention can fill more easily the mould cavities, even those with complex design, allowing to reduce injection moulding pressure, with less problems of warpage, and to reduce moulding cycle times with an economical advantage in terms of productivity.
• compositions of the invention are suitable to mould under-the-hood parts in the automotive industry for applications requiring outstanding mechanical properties also at high temperatures.
• test is carried out according to ISO 899 on ISO T bars specimens (same as for tensile modulus, ISO 527- type IA).
• the test conditions are:
• Filled compositions are prepared by extruding the same PP-I, PP-2, PP-3 and PP-4 polymer materials used in the previous examples (component A)), with a component B) selected from:
• the extrusion is carried out in a single screw extruder, cokneader Buss model MDK70 with
• component A) is fed through the first feeding port while component B) is preferably fed through two vertical feeding ports in the melt phase.
• the operating parameters are the following:
• Screw speed 270 rpm
• Barrel temperature 200 - 230 0 C.
• a strand die plate with cooling bath and strand cutter is used to form pellets; vacuum degassing is also applied to extract fumes and decomposition products.
• the final properties of the so obtained compositions are reported in Table X, together with the relative amounts of the components.
• the spiral flow test is carried out as previously described.

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Compositions Of Macromolecular Compounds (AREA)

Priority Applications (5)

Applications Claiming Priority (4)

Publications (1)

Family

ID=39061253

Family Applications (1)

Country Status (3)

Cited By (23)

Families Citing this family (4)

Citations (3)

Family Cites Families (10)

• 2007
  • 2007-12-12 JP JP2009541996A patent/JP5237964B2/ja active Active
  • 2007-12-12 EP EP07857486.0A patent/EP2092004B1/de active Active
  • 2007-12-12 WO PCT/EP2007/063823 patent/WO2008074713A1/en active Application Filing

Patent Citations (3)

Also Published As

Similar Documents

Legal Events